1. Field of the Invention
This invention relates to drive wheels on a shaft and more particularly to wheels which can be fixed to the drive shaft or rotate freely on the drive shaft.
2. Description of the Related Art
In many powered devices wheels are directly connected by a drive shaft to a motor. There are no clutches, speed changing gears or reverse gears to keep the cost and weight of the device down. When the motor is on, the wheels are powered by a direct connection from the motor through the drive shaft to the wheels. When the power is off the device becomes hard to push or pull since the wheels and the drive shaft are still connected to the motor. Some devices have a second set of wheels used when pushing or pulling the device. These wheels may be used when the device is tilted onto the second set of wheel by pushing the handle used for pushing and pulling the device downward and raising the drive wheels off the ground. The tilting requires quite a bit of effort to keep the drive wheels off the ground while pushing or pulling the device.
It is desired to have a device, which can easily be pushed or pulled on its drive wheels when the motor is off.
A drive shaft is attached to a motor and to a pair of drive wheels on other side of a motor driven device. A roller bearing placed between the drive wheel and the shaft can be used to rotate the wheel on the drive shaft without turning the drive shaft. The a wheel hub connected to the wheel has a pin through it and the drive shaft to stay fixed to the drive shaft when the motor is driving the device. The pin can be removed from the wheel hub and the drive shaft when it is desired to have the drive wheels turn freely to push or pull the device. By removing a pin for each wheel both wheels can turn freely to push or pull the device. When the device has power available again the pins can be reinserted and the device driven by the motor again.
It is an object of the invention to easily disengage a wheel from a drive shaft so that it can rotate without rotating the drive shaft.
It is an object of the invention to easily push or pull a motor driven device having a direct drive from the motor to the drive shaft when the motor is not on.
It is an object of the invention to retrofit old devices with the disengageable wheels.
Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings.